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3 years ago

Solve for the variable k^2+9k=0

Mathematics

1 answer:

pshichka [43]3 years ago

3 0

Answer:

Step-by-step explanation: two solution found is -9 and 0 that is the right answer

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The equation of a circle is (x + 3)2 + (y – 5)2 = 81. Determine the coordinates of the center of the circle and the length of th

Nataly_w [17]

Answer:

The center of the circle is (-3 , 5) and the length of the radius is 9 units

Step-by-step explanation:

* Lets revise the standard form of the equation of the circle

- The center-radius form of the circle equation is in the format

(x – h)² + (y – k)² = r², where the center is the point (h, k) and

the radius is r.

- This form of the equation is helpful, because you can easily find

the center and the radius.

* Now lets solve the problem

- The equation is (x + 3)² + (y - 5)² = 81

- By comparing the two equations

∵ (x – h)² + (y – k)² = r² and (x + 3)² + (y - 5)² = 81

# x - h = x + 3

∴ -h = 3 ⇒ divide both sides by -1

∴ h = -3

# y - k = y - 5

∴ k = 5

# h and k are the coordinates of the center of the circle

∴ The center of the circle is (-3 , 5)

# r² = 81 ⇒ take √ for both sides

∴ r = 9

∴ The length of the radius = 9 units

* The center of the circle is (-3 , 5) and the length of the radius is 9 units

3 0

3 years ago

If sam has 1 gallon of milk and he drinks 4 glass of 8 ounces how many dayswould he have drank the milk gone?

Mariulka [41]

1 gallon = 4 quarts

1 quart = 32 ounces, 1 quart = 32 ounces*1 glass/8 ounces = 4 glasses

1 quart = 4 glasses

1 gallon = 4 quarts = 16 glasses

If Sam drinks 4 glasses per day. and he has 16 glasses, then 16/4 = 4 days

Answer is 4 days.

3 0

3 years ago

Solve x2 + 8x + 22 = 0 by completing the square.

Liula [17]

Answer:

Step-by-step explanation:

the solution of a squared equation is

x = (-b ± sqrt(b² - 4ac)) / (2a)

in our case

a = 1

b = 8

c = 22

x = (-8 ± sqrt(64 - 88))/2 = (-8 ± sqrt(-24))/2 =

= (-8 ± sqrt(4×-6))/2 = (-8 ± 2×sqrt(-6))/2 =

= -4 ± sqrt(-6) = -4 ± i×sqrt(6)

6 0

2 years ago

tim brought a car 25000 and it depreciation $350 per year. What is the value of the car after 6 years?

blondinia [14]

Answer:

22900

Step-by-step explanation:

multiply 350 by 6 and get 2100

subtract 2100 from 25k and get 22900

6 0

3 years ago

Read 2 more answers

Compound interest In Exercise,$3000 is invested in an account at interest rate r,compounded continuously.Find the time required

xenn [34]

Answer:

(a) 8.15

(b) 12.92

Step-by-step explanation:

Given: P = $3000, r = 0.085

$A = Pe^{rt}$

Where

A is the Amount

P is the Principal

r is the rate

t is the time

(a) For the amount to double, A = 2 × P

A = 2 × $3000

A = $6000

$6000 = 3000e^{0.085t}$

$\frac{6000}{3000} = e^{0.085t}$

$2 = e^{0.085t}$

Take $log_{e}$ of both sides

$log_{e}2 = log_{e}e^{0.085t}$

But $log_{e}e = 1$

∴ $ln2 = 0.085t$

$t = \frac{ln2}{0.085}$

$t = \frac{0.693}{0.085}$

t = 8.15

(b) For the amount to double, A = 3 × P

A = 3 × $3000

A = $9000

$9000 = 3000e^{0.085t}$

$\frac{9000}{3000} = e^{0.085t}$

$3 = e^{0.085t}$

Take $log_{e}$ of both sides

$log_{e}3 = log_{e}e^{0.085t}$

But $log_{e}e = 1$

∴ $ln3 = 0.085t$

$t = \frac{ln3}{0.085}$

$t = \frac{1.0986}{0.085}$

t = 12.92

5 0

3 years ago